I think most players are just overpriced recently which is why they always fail to live up the price tag. We have seen a lot of players end up like that so now it's just like a gamble for team when buying a player, they may end up performing well but most times they they don't so I am not surprised. When these players are still playing for a smaller team they look as as if they are good but most they are not fit to play in top teams. I think Vlahovic is not that bad but the injuries affected him along the way because he started well for them and even caught the eyes of several clubs like Chelsea. A business can not always be good so teams just have to be careful how they spend money to buy players.
For the price of the player does look very expensive in a few seasons so that it limits a number of clubs to recruit him. Expectations of players whose prices are too high sometimes also not comparable to the performance given and that is why most teams will think about adjustments before recruiting. Injury is the main factor that makes a number of players fail to shine and it is influenced by mistakes that may be too forced to play because a number of teams do not have a good squad depth.
The beginning of the Vlahovic season is good at helping the team but as you say because after entering the second half of his performance season it declined. If you are not careful in choosing players, what happens sometimes does not go well because the purchase is not based on the needs of the team.
Oh yes one more thing, now Juventus has also installed a clause for Douglas Luiz of € 25M price tag. And Man United is linked with:
Manchester United are really looking to improve their team and I like the way they want to totally rebuild their team. I have seen some impressive signings they made and of course Douglas Luiz is not a bad player and having a premier league experience is a good thing. With the right salary I don't think it will be difficult to get him.
For Man United there may be a special board that we can discuss, but I responded a little about how the reshuffle was carried out by the team with the totality of rebuilding the squad they had. This will show a new direction for Amorim if it goes according to the scenario they have built, even though success cannot be achieved so quickly.